The carapace is represented as transparent. The appendages have been removed, but the outlines of the left entocoxites (6) have been sketched in. The positions of the abdominal appendages are indicated by the external branchial muscles (17), the branchial cartilages (19), the tendinous stigmata (18), and the abdominal endochondrites (21). In the cephalothorax (1) all the tergo-coxal and plastro-coxal muscles have been dissected away, leaving the endosternite (11) with the occipital ring exposed. One of the left tergo-proplastral muscles (4) and the left branchio-thoracic muscles (16) are represented. The longitudinal abdominal muscles are also seen. All the muscles of the right side have been omitted except the haemo-neural muscles (23), of which the last two are represented upon the left side also. At the base of the telson the flexors (29) and extensors (27) of the caudal spine are represented as cut off near their insertions. The sphincter ani (26), levator ani, and occludor ani (25), and their relations to the anus (28), are shown. The oesophagus runs forward to the proventriculus (3). From this the intestine (20) passes posteriorly. The brain lies upon the neural side of the endosternite, and the ventral cord (22) passes back through the occipital ring. The neural nerves are cut off, but the left haemal nerves and those from the fore-brain (12) are represented entire. The first pair of neural nerves go to the chelicerae. The second to sixth pairs go to the next five cephalothoracic appendages, which are represented by the entocoxites (6). The seventh pair of neural nerves go to the chilaria, and the eighth pair to the operculum. The neural nerves from the ninth to the thirteenth arise from the abdominal ganglia and innervate the five pairs of gills. From the fore-brain a median olfactory nerve (9) and two lateral ones (8) pass forward to the olfactory organ; a median eye-nerve (2) passes anteriorly and haemally upon the right of the proventriculus (3) to the median eyes; and a pair of lateral eye-nerves pass to the lateral eyes (15). The first haemal nerve, or lateral nerve, follows the general course of the lateral eye-nerve, but continues posteriorly far back on to the neural side of the abdomen. The haemal nerves of the hind-brain radiate from the brain to the margins of the carapace, and each one passes anterior to the appendage of its own metamere. The integumentary portions divide into haemal and neural branches, of which the haemal branches (5) are cut off. Each haemal branch gives off a small nerve which turns back toward the median line upon the haemal side of the body.